Flexible surgeon's gloves have very demanding requirements. They should have strength to resist tearing and should be thin and flexible to allow touch sensitivity. Further, they should be easy to don with wet or dry hands, but not be slippery for handling instruments.
Traditionally, surgeon's gloves have been manufactured by dipping molds or forms shaped like hands into baths containing natural rubber latex emulsions to form a film of the desired thickness. The film is then cured and the glove is removed from the mold. There are numerous problems with the manufacture and use of natural rubber gloves, an important one of which is the step of removal from the mold form. Removal from the mold can be difficult because the cured latex tends to be tacky and may adhere to the mold. Further, plain natural rubber latex gloves adhere to themselves and tend to be very difficult for a surgeon to don. This is particularly true in actual use situations where a sterility protocol is followed with the surgeon having wet hands. Techniques for addressing these problems have developed over the years. Initially, mold-release powders were dusted onto the surface of the mold forms to facilitate the removal of the glove from the form. Since the gloves are generally turned inside out as they are stripped from the form, these powders then aided the subsequent donning of the glove by the surgeon.
A wide variety of powders including talc, lycopodium, calcium carbonate, starch and modified starches has been used. Problems were identified with granuloma formation in patients and attributed to powders, particularly talc and its use has long been abandoned. Powdered gloves are still widely accepted today with epichlorohydrin modified starches being used quite successfully as powders for gloves by carefully controlling the material used and the amounts present on each glove.
As an alternate to powder, there are many disclosures of coating or treatments of gloves to modify their surface properties. These surface modifications have enjoyed varying degrees of success, as high quality powdered gloves are still considered optimum in terms of strength, tactility and ease of donning and removal.
There are two general ways of achieving natural rubber latex gloves which do not require powder for donning, chemical treatment of the rubber surface and adding materials onto a natural rubber surface. Representative of the chemical treatment is halogenation. Halogenation renders a rubber surface slippery, but it is most effective in conjunction with dry hands and additionally, the treatment may weaken and embrittle the overall film. It may also adversely affect the shelf life of a sterile glove.
There are many disclosures relating to adding materials to a rubber surface to improve its slip characteristics with both wet and dry skin. Representative of the disclosures is U.S. Pat. No. 4,575,476 to Podell et al. Podell et al. teaches a dipped rubber article having a skin contacting surface layer formed of a hydrogel polymer, such as polyvinyl pyrrolidone, polyhydroxyethyl acrylate or methacrylate and copolymers of these with each other or with acrylic or methacrylic acid, or with 2-ethylhexyl acrylate or a ternary copolymer of 2-hydroxyethyl methacrylate, methacrylic acid and 2-ethylhexyl acrylate.
Gloves prepared according to the teaching of Podell et al. can be shown to have less mechanical strength and reduced resistance to accelerated aging after sterilization compared to conventional powdered latex gloves. Under conditions of mechanical stress, such as extreme elongation as could occur during donning, they may partially delaminate and lose particles from the hydrogel coating. Further, they tend to be some what thicker than many powdered latex gloves thereby adversely affecting tactile sensitivity.